1908] 



HEGNER^ THREE CHRYSOMELID BEETLES 



23 



days; 287 between June 22 and Aug. 1, 41 days; 352 betvreen June 11 and Aug. 31, 

 82 days; 234 between June 25 and Aug. 3, 40 days. This is sufficient to show the 

 quantity of eggs laid by a single female during its life, the average of 54 i-ceords being 

 315. 



There is no definite niniiber of hours constituting the hatching period as the time 

 varies from 4 to 7 days according to conditions of temperature and moisture. The 

 average for many batches was 5§ days. All the eggs of one batch. are in approximately 

 the same stage of development and the larvae grow up together, — all pupating at 

 about the same time. Larval life ranges from 17 to 24 days, 20 days being the aver- 

 age. Food conditions are no doul)t responsible for the rapid growth of some larvae 

 and the slow growth of others. The pupal period is usually 12 days although many 

 emerge in 11 days and a few linger on to 13 or 14 days. The entire period then from 

 the laying of the egg to the emergence of the imago is 38 days although a fevr covered 

 this period in 35 days and others occupied 40 days.. 



The sexes of the imago are distinguishable because of the larger size of the 

 female. A number of beetles were allowed to select their own mates; others vv'ere 

 artificially paired. Copulation occurred from 6 to 10 days after emergence and the 

 first eggs were laid 10 to IG days later making the entire cycle a period of 64 days. 



The eggs are differently colored and of different sizes in the three species studied. 

 Those of C. higshyatia are the smallest 

 and are straw colored ; those of C. multi- 

 punctaia are slightly larger and are light 

 orange in color; while the eggs of C. 

 lunata are white and are larger than 

 either of the other tAvo. The figure gives 

 a good idea of the comparative sizes. iVs 

 may be expected, the newly hatched 

 larvae have a ground color similar to 

 the color of the egg being straw colored, 

 light orange, and white according to the 

 species. 



Pedigreed material raised in the laboratory was experimented with in an effort 

 to learn the results of hybridizing different species. Pure specimens of C. higshyana 

 and C. multipundata crossed freely, their eggs being always fertile. The eggs and 

 larvae produced by these crosses were of course in size and color like those of the 

 female parent. No differences were noted in the size or coloration of the hybrids 

 imtil emergence when the resultant beetles were always intermediate between the two 



Fig. 1. Eggs of C. bigsbyana. Fig. 2. Eggs of 

 C. multipundcita. Fig. 3. Egg of C. lunata. 



